Low-foaming, pH sensitive, alkylamine polyether surface active agents and methods for using

ABSTRACT

Alkylamine polyether surface active agent compositions and methods for using are described. The instant compositions are low foaming, and pH sensitive and are generally of the structure: ##STR1## in which (a) R 1  may be hydrogen or alkyl; 
     if R 1  is hydrogen then R 2 , R 3  and R 4  must be alkyl having a total number of carbon atoms falling in the range of 7 to 23; 
     if R 1  is alkyl, then R 2 , R 3  and R 4  may be alkyl or hydrogen, the total number of carbon atoms in R 1  +R 2  +R 3  +R 4  falling in the range of 7 to 36 (preferably about 10 to 20); 
     (b) The --(C 2  H 4  O) m  --segment must be a poly(oxyethylene) homogeneous chain or &#34;block&#34; polymer (i.e., a homopolymer), m having an average value in the range of 1 to 15, preferably 5 to 13; and 
     (c) Y is selected from the group consisting of: 
     (1) homogeneous poly(oxypropylene) chain (PO) &#34;block&#34; polymer or residue (i.e., a homopolymer), of the structure--(C 3  H 6  O) n  H, having a value in the range of 1 to 50, preferably 6 to 30; 
     (2) hydrophobic end cap (e.g., --CH 2  --0); and 
     (3) hydrophobic end capped polyoxypropylene residue. 
     A particularly preferred class of surfactants of the instant invention constitutes 1,1,1-trialkylmethylamine ethyleneoxy(EO)-propyleneoxy(PO) polyethers having from 1 to 15 moles of ethyleneoxide residue and from 1 to 50 moles of propyleneoxide per mole of alkylmethylamine. 
     The methods of the instant invention generally relate to the production of paper from secondary fiber. Unexpectedly, the compositions of the instant invention are found to be applicable in the common methods employed very pH sensitive, size-safe and to produce paper products from secondary fiber.

This is a division of application Ser. No. 06/406,885, filed Aug. 10,1982.

This invention relates to a new composition of matter and methods forusing said composition. The new compositions are a specific alkylaminepolyoxyalkylene or polyether surface active agents (surfactants)comprising: (a) a hydrophobic moiety comprising one or more aliphaticgroups which is connected to (b) a secondary or tertiary amine segmentwhich is in turn connected to (c) a single polyether segment comprisingpoly(ethylene-oxy) (EO) and poly(propylene-oxy) (PO) or hydrophobic endcaps e.g., benzyl adduct. The methods of the present invention relateprimarily to the manufacture of paper from secondary fiber. Of criticalimportance to achieve the important composition and method advantages ofthe present invention is the number of moles of EO and PO and thepresence of an end cap, if employed.

PRIOR ART

U.S. Pat. Nos. 3,117,999 and 3,118,000, both assigned to Rohm and HaasCompany, disclose compositions which are related to the compositions ofthe present invention. The U.S. Pat. No. 3,117,999 discloses compoundsof the formula: ##STR2## in which R₁, R₂ and R₃ are alkyl groups whosetotal carbon content ranges from 7 to 23, a is an integer of from 15 to45, b is a number of from 15 to 67.5, and the relation of b:a is 1:1 to1.5.1; or ##STR3## in which R₁, R₂ and R₃ are the same as before, a+cequals an integer of from 15 to 45, b+d equals a number of from 15 to67.5, and the relation of (b+d):(a+c) is 1:1 to 1.5:1

U.S. Pat. No. 3,118,000 discloses compounds of the formulae: ##STR4## inwhich Q=R₃ O or R₄ NH; R₁ and R₂ =CH₃ or H;

with R₁ =CH₃ when R₂ =H and R₂ =CH₃ when R₁ =H;

R₃ consists of an alkylated phenyl containing a total of 4 to 18 carbonatoms in the alkyl group or a straight or branched chain alkyl grouphaving 8 to 18 carbon atoms;

R₄ is a straight chain alkyl group with 8 to 18 carbon atoms.

Nonionic surfactants which are capable of being protonated ordeprotonated depending upon the hydronium ion (H⁺) concentration oftheir environment (i.e., their pH) are described in Rohm and HaasCompany Speciality Chemicals TRITON R-W Surfactants pamphlet CS-450,dated September, 1978. This pamphlet describes the protonation ofnonionic surfactants containing amine functionality according toEquation I. ##STR5## As noted in the CS-450 pamphlet, the TRITON R-Wseries are polyethoxyalkylamines wherein n in Equation I has a value of1, 2, 3, 5, 7.5, 10, 12.5, and 15, there being no further specificity ofthe structure "R".

Finally, Rohm and Haas Company's publication SP-127 titled, "PriminoxPolyethoxy Amines" dated 12/59 describes polyethylene oxide derivativesof 1,1,1-trialkylmethyl amines (hereafter sometimes referred to as"TAMA"). "Priminox R" series are described as the reaction products of"Primene 81-R" (a 12-14 carbon TAMA) with ethylene oxide. "Priminox T"series are described as the reaction product of Primene JM-T (an 18-22carbon TAMA) with ethylene oxide. This pamphlet does not disclose norsuggest that "Priminox R" or "T" series may be polypropoxylated, nor theadvantages thereby obtained.

THE PRESENT INVENTION

The present invention provides unexpected pH sensitivity resulting insize enhancement, carefully controllable foaming tendency (describedbelow), recyclability and numerous other advantages in various methodsof paper manufacture, especially those which employ secondary fibersources (i.e., non-virgin or recycled fiber). These advantages areachieved by means of nonionic surfactants of the structure: ##STR6## inwhich (a) R₁ may be hydrogen or alkyl;

if R₁ is hydrogen then R₂, R₃ and R₄ must be alkyl having a total numberof carbon atoms falling in the range of 7 to 23;

if R₁ is alkyl, then R₂, R₃ or R₄ may be alkyl or hydrogen, the totalnumber of carbon atoms in R₁ +R₂ +R₃ +R₄ falling in the range of 7 to 36(preferably about 10 to 20);

(b) The --(C₂ H₄ O)_(m) --segment must be a poly(oxyethylene)homogeneous chain or "block" polymer (i.e., a homopolymer), m having anaverage value in the range of 1 to 15, preferably 5 to 13; and

(c) Y is selected from the group consisting of:

(1) homogeneous poly(oxypropylene) chain (PO) or "block" polymer orresidue (i.e., a homopolymer), of the structure--(C₃ H₆ O)_(n) H, "n"having a value in the range of 1 to 50, preferably 6 to 30;

(2) hydrophobic end cap (e.g., --CH₂ --φ; and

(3) hydrophobic end capped polyoxypropylene residue.

The instant novel compounds provide enhanced foam control at desiredoperating temperatures. In the preferred EO-PO polyethers (which have apolyether chain molecular weight in the range of 100 to 4,000,preferably about 700 to 2,500), foam control is accomplished byselecting the length of the EO and PO blocks and PO/EO ratio accordingto foam break temperatures (described below), while limiting total EOand PO to maintain the hydronium ion sensitivity. It has been found thatthe hydronium ion sensitivity is slight to nil when the EO's and PO'sexceed 15 and 50 respectively whether of block or heteric design. It hasalso been found that the temperature/foam control specificity isdependent on block alkoxylation and essentially unattainable withheteric polyethers.

DETAILED DESCRIPTION OF THE INVENTION Compositions

Synthesis of the novel surfactants of Formula V is normally a two stepprocess starting with the reaction of an alkylamine having the generalstructural formula: ##STR7## wherein R₁ R₂, R₃ and R₄ have the valuesstated above) and from about 1 to 15 moles (preferably from about 7 toabout 13 moles) of ethylene oxide (EO). This reaction (which, asdescribed, is accomplished in two steps) produces an intermediate whichis then subsequently propoxylated or end capped (or both). Formula VIembraces at least two classes of alkylamines depending upon whether R₁is hydrogen or alkyl. In the case where R₁ is alkyl, R₂, R₃ and R₄ maybe independently hydrogen or alkyl having in total (with R₁) about 7 to36 carbon atoms (preferably about 10 to 20 carbon atoms). R₁ being alkylis intended to include intermediate alkylamine polyethers of thestructure ##STR8## (a and b are integers which may be the same ordifferent) which would then be reacted with propylene oxide or withe.g., benzyl chloride (or both), to complete the composition. Alkylaminepolyethers of this structure have been found to possess high pHsensitivity as defined herein.

In the instance where R₁ is hydrogen it is necessary that R₂, R₃ and R₄each be alkyl having in total about 7 to 23 carbon atoms. In thispreferred class of alkyl amines, it will be recognized that the aminelinkage is secondary, linking the polyether segment and a1,1,1-trialkylmethyl hydrocarbon segment. Thus, the preferred polyethersherein are of the structure ##STR9## in which (a) R₁ must be hydrogen;

(b) R₂, R₃ and R₄ must be at least methyl groups, the total carbon atomsof R₂ +R₃ +R₄ falling in the range of 7 to 23;

(c) the --(C₂ H₄ O)_(m) --segment must be a poly(oxyethylene)homogeneous chain block polymer, m having an average value in range of 1to 15; and

(d) the --(C₃ H₆ O)_(n) --segment must be a homogeneouspoly(oxypropylene) chain block polymer, n having a value in the range of1 to 50.

In the two classes of alkyl amines discussed above, amine functionalityis tertiary in the former and secondary in the later. By the definitionsof R₁, R₂, R₃ and R₄ specified herein alkyl amine polyethers of thestructure ##STR10## are excluded.

This exclusion is intended because such materials surprisingly do notexhibit pH sensitivity. This is evident from Table 1 where commercialamine ethoxylates of the type excluded above are compared via their"pH-sensitivity" (measured here as surface tension sensitivity) todialkylamine alkoxylates and 1,1,1-trialkylmethyl primary aminealkoxylates. It will be seen from Table 1 that non-propoxylatedmaterials do exhibit a small level of Ph sensitivity (materials 2 and 3from the top). However, the propoxylation of these materials wouldreduce their pH sensitivity to essentially zero (compare materials 4 and5 and 6 and 7).

                                      TABLE 1                                     __________________________________________________________________________    Change in Surface Tension between pH = 12 and pH = 2 for                      various amine polyethers (0.1% w/w, T = 20° C.)                                               SURFACE TENSION (dynes/cm.sup.2) AT                                           pH                                                     COMPOUND               12 10  8  6  4   2                                     __________________________________________________________________________    M-310 (Texaco)         38.9                                                                             38.9                                                                              37.4                                                                             37.3                                                                             37.5                                                                              35.5                                   ##STR11##                                                                    Ethoduomeen T/20 (Armak)                                                                             41.2                                                                             39.7                                                                              41.2                                                                             42.5                                                                             46.0                                                                              45.2                                   ##STR12##                                                                    3x = 10                                                                       Ethomeen S/20 (Armak)  39.4                                                                             39.0                                                                              38.8                                                                             41.0                                                                             45.8                                                                              46.4                                   ##STR13##                                                                    di-n-hexylamine decaethoxylate                                                                       28.0                                                                             31.0                                                                              49.0                                                                             54.0                                                                             54.8                                                                              54.0                                   ##STR14##                                                                    di-n-hexylaminedecaethoxylate pentapropoxylate                                                       30.2                                                                             32.4                                                                              42.0                                                                             42.0                                                                             42.0                                                                              42.8                                   ##STR15##                                                                    Primene 81R-decaethoxylate                                                                           31.0                                                                             32.0                                                                              48.5                                                                             49.5                                                                             52.0                                                                              52.5                                   ##STR16##                                                                    Primene 81R-decaethoxylate hexapropoxylate                                                           31.4                                                                             33.7                                                                              41.6                                                                             45.0                                                                             47.0                                                                              45.1                                   ##STR17##                                                                    __________________________________________________________________________

In any event, whether the amine linkage is secondary or tertiary thealkyl group or groups to which the nitrogen atom is bonded provide thehydrophobic portion of the surfactants herein disclosed. It is for thisreason that "hydrocarbon" means consisting primarily of hydrogen andcarbon so as to be hydrophobic. It is critically important to achievethe advantages of the present invention that the hydrocarbon group orgroups of the instant surfactants be hydrophobic. One skilled in the artwill recognize that this constraint must be met in order for the overallmolecule to exhibit surfactant properties such as surface tensionreduction, interfacial tension, wetting, penetration, emulsification,foaming and detergency when synthesis is completed. The preferred 1,1,1trialkylmethylamine starting materials are commercially available fromthe Rohm & Haas Company under the trade designation "Primene".Ethoxylated "Primene" surfactants also are available from Rohm and HaasCompany as described in "TRITON" RW-Surfactants, Rohm & Haas Companytechnical publication FCS-450 dated September, 1978. The "TRITON" RWseries are polyethoxyalkylamines made by the reaction of TAMA withethylene oxide. According to titration and spectroscopic analysis, the"TRITON" RW surfactants appear to have a highly branched1,1,1-trialkylmethylamine structure, R₁ +R₂ +R₃ having a total of 12 to14 carbon atoms.

In the alternative, the preparation of the preferred polyalkoxylated1,1,1-trialkylmethylamines is described in the U.S. Pat. No. 2,871,266,issued Jan. 27, 1959 to Rohm & Haas Company. The '266 patent teaches atwo-step method for preparing polyoxyalkylated derivatives of1,1,1-trialkylmethylamines, there being from 5 to 100 moles of ethyleneoxide, propylene oxide (or both) added to the 1,1,1-trialkylmethylaminesas is more fully discussed below. The compositions of the '266 patentdiffer from the compositions of the present invention in that no mentionis made nor is there any recognition of the advantages of blockpoly(ethyleneoxy)-poly(propyleneoxy) derivatives of the1,1,1-trialkylmethylamines.

As is noted above, hydrophobic segment or segments of the presentmolecule are connected by means of a nitrogen linkage to a polyethermoiety in what is ultimately a secondary or tertiary amine. Whether theamine is secondary or tertiary, it is critically important that theamine nitrogen have but single oxyalkylation. Alkyl amines with morethan one polyether chain are simply not pH sensitive.

According to U.S. Pat. No. 2,871,266, reaction of the preferred TAMAwith the ethylene oxide is most conveniently accomplished by mixing anacid catalyst with TAMA alone or with an organic solvent such as naptha,benzene or toluene. The temperature employed in the reaction may bebetween 20° C. and 180° C., preferably 60° C. and 95° C., particularlywhen a hydrochloric acid catalyst is used. Ethylene oxide is then passedinto the TAMA-catalyst mixture. The use of above atmospheric pressure isoptional. It is described in the literature that the addition of thefirst mole of ethylene oxide occurs fairly easily, particularily whenthe C₈ or C₉ amines are employed. Subsequent moles of ethylene oxide areadded less easily than the initial mole, particularly as the size of thehydrocarbon moiety increases until at about C₁₄ to C₁₆ only a singlemole of ethylene oxide can be added under any conditions which employ anacid catalyst.

As described in U.S. Pat. No. 2,871,266, subsequent moles of ethyleneoxide are most easily added to the monoethoxylated TAMA when, afteraddition of the first mole of ethylene oxide, the acid catalyst isneutralized (e.g. with a base such as sodium hydroxide, sodiumcarbonate, potassium hydroxide, etc.) and an alkaline catalyst such asan alkaline metal hydroxide (including sodium or potassium hydroxides)is employed. Alkali metal alcoholates such as sodium methoxide,potassium ethoxide or sodium butoxide also may be desirable alkalinecatalysts. The reaction to add subsequent moles of ethylene oxide may beperformed at ordinary pressures or elevated pressures (usually apressure from about 10 to 20 p.s.i. [60 to 120 kPa]) provides a rapidrate of reaction at temperatures between 100° C. to 200° C. Thepreferred reaction temperature range is 130° C. to 170° C.

In order to synthesize the surfactants of the present invention it isnecessary to condense on the amine group a single block polyether chainhaving from 1 to 15 moles of ethylene oxide (preferably 7-13 moles). Itis critically important that the ethylene oxide chain be homogeneous.Stated otherwise, the present invention contemplates that the ethyleneoxide polyether segment will be a homopoloymer or "block" polymer.Addition of mixtures of ethylene oxide or propylene oxide (or otherepoxides) or the condensation of other than ethylene oxide with thepreviously described alkylamines are outside the scope of the presentinvention. It is only when this critically important requirement isobserved that the advantages of the present invention are achieved.

To complete the synthesis of the composition of the present invention,it is necessary to add to the end of the polyethylene oxide chain a morehydrophobic, less polar second polyether chain having either 1 to 50moles of propylene oxide, (preferably 6 to 30 moles), hydrophobic endcap, or a mixture with a plurality of moles of propylene oxide betweenpolyEO and the end cap. In other words, the present inventioncontemplates in its preferred aspect the addition of a "block" orhomopolymer chain of polypropylene oxide on the hydroxy end portion ofthe polyethylene oxide intermediate previously condensed with thealkylamine.

After the two-step addition of ethylene oxide to the alkylamine,addition of propylene oxide proceeds in a single step. Propylene oxidereacts relatively smoothly with the hydroxy-terminated ethylene oxidechain to produce compositions of this invention. The propylene oxideblock polyether chain is best added using basic catalysts such as sodiumhydroxide, sodium carbonate, potassium hydroxide, potassium carbonate,or calcium hydroxide. Thus, from one to fifty moles of propylene oxide(preferrably 6-30 moles), are added to the alkylamine ethylene oxideintermediate.

In a less preferred aspect of the present invention, it is possible toreplace a portion or the entirety of the polypropylene oxide chain orblock with an end cap e.g., a benzyl group. Other end caps which couldbe employed herein include methyl, ethyl, propyl, isopropyl or t-butyl.Thus, for example, if benzyl termination is desired, benzyl chloridecould be condensed with the hydroxy-terminated polyethylene oxidealkylamine intermediate. Benzyl termination has been found to beapproximately the equivalent (in terms of foam control) of 8 moles ofpropylene oxide, particularly within the methods contemplated in thepresent invention. Since it is possible to control the addition ofpolypropylene oxide to the polyethylene oxide intermediate (to add from2 to 6 moles), benzyl termination is not preferred because it does notprovide the same ability to control foam and temperature performance.

It is within the definition of the present surfactants that abenzyl-terminated polypropylene oxide segment could be employed in placeof a just benzyl termination or just polypropylene oxide. Since benzyltermination is roughly the performance equivalent of about 8 moles ofpropylene oxide, substitution therewith is definitely contemplated. Thismeans the ranges of propylene oxide would be from 1 to 42, preferably 6to 22 if benzyl termination of the polypropylene oxide chain is desired.Similarly, other end caps can be utilized with suitable reduction in thenumber of moles of propylene oxide.

Several other synthetic methods have been or can be employed to condensethe amine and ethylene oxide. One method for accomplishing suchcondensation is described in U.S. Pat. No. 4,112,231, assigned to BerolKemi AB issued on Sept. 5, 1978. In particular, the '231 patentdescribes a method for condensation of epoxides with organic compoundshaving active hydrogens such as alcohols, polyols, and amines employinga neutral inorganic salt selected from the group consisting of sodiumfluroborate, magnesium perchlorate, calcium perchlorate, manganeseperchlorate, nickel perchlorate and zinc perchlorate. The '231 patentdescribes the preferred catalyst as zinc perchlorate. The reactionconditions of the U.S. Pat. No. 4,112,231 Patent are within the range of80° C. to about 200° C. and preferably within the range of 100° C. to150° C. The reaction temperature in all cases is below the decompositiontemperature of the reactants thus increasing the yield. Utilization ofan inert organic solvent and optionally employing pressurized reactionvessels also is described. U.S. Pat. No. 3,117,999 describes thecatalyst system of alcohol and water, the reaction condition being 80°C. and a pressure of 20 to 30 pounds per square inch (120 to 150 kPa).

The compositions of the present invention are highly "pH sensitive". Asthe terms employed herein pH sensitivity means that by mere adjustmentof the acidity or basicity of the aqueous environment in which thepresent compositions are employed, it is possible to control the extentto which these compositions behave as surface active agents. Putsuccinctly, at pH's above approximately 8, the present compositions arenonionic surfactants which exhibit all the advantageous detergency,defoaming, surface tension reduction, etc. properties common to suchnonionic surfactants. As the pH of the aqueous environment in which theyare dispersed is reduced below 8 (i.e. the instant surfactants begin toencounter a medium of greater acidity), the amine functionality becomesprotonated (see Equation I), thereby creating a cationic surface activeagent. (This shift in properties occurs at around pH=7-9, depending uponwhich catalyst or which amine is employed.) The resulting cationicsurface active agents do not exhibit the advantageous properties ofnonionic surfactants, i.e., they do not stabilize otherwise immisciblesuspensions such as oil in water. These cationics tend to be hydrophilicin their properties and thus tend to collect in aqueous media. Inpractical terms, this means that if an oil and water emulsion (e.g.,printer's ink in water) is stabilized by means of the surfactants of thepresent invention at high pH, reduction of the pH (i.e. by the additionof acid) will break the emulsion and the oil and water separate intolayers. As a further example a C₁₂ -C₁₄ trialkylmethylamine-(EO)₁₀--(PO)₁₂ has a foam break temperature (defined below) and a cloud pointof around 65° F. (18° C.). In an alkaline solution at 100° F. (37° C.)it is not soluble but in a dispersed cloudy state (over its cloudpoint). Yet, when acidified, the solution clears indicating thequaternized analogue is more water soluble. Other measurable phenomenawhich change as the pH of the present surfactants is dropped includeloss of detergency, and increase in surface tension.

Sensitivity to pH is alluded to in some of the technical literaturepublished by the Rohm & Haas Company. However, these discussions werewith reference to block ethylene oxide, 1,1,1-trialkylmethylaminederivatives only, and not with surfactants having both ethylene oxideand propylene oxide blocks (or equivalents) contemplated by the presentinvention.

More particularly, U.S. Pat. No. 3,117,999 and U.S. Pat. No. 3,118,000(both assigned to Rohm & Haas Company), employ EO in the range of 15 to45 and PO in the range of 15 l to 67.7, the ratio of n over m being inthe range of 1:1-1.5:1. These materials exhibit little or no pHsensitivity, nor the low foaming characteristics of the materials of theinstant invention because the polyether segments are too large. This isdemonstrated in the "change" column of Table 2 where the surface tensiondifference approaches zero as moles of EO and PO increase. Thisdemonstrates the adverse effect of increasing molecular weight on pHsensitivity.

                  TABLE 2                                                         ______________________________________                                        Change in Surface Tension between pH = 12 and pH = 2 for                      1,1,1-trialkyl methyl amine polyethers of the structure:                       ##STR18##                                                                                     Surface Tension                                                               dynes/cm.sup.2                                               m    n      Foam Break °F. (°C.)                                                           pH 12.0                                                                              pH 2  Change                                ______________________________________                                        7.5   0     136 (58)       32.5   47.5  15.0                                  7.5   6     77 (25)        34.3   44.6  10.3                                  7.5   9     67 (19)        35.3   43.0  7.7                                   7.5  12     56 (13)        35.9   42.0  6.1                                   7.5  18     50 (10)        37.0   40.4  3.4                                   10.0  0     165 (74)       33.0   49.6  16.6                                  10.0  6     97 (36)        34.5   47.0  12.5                                  10.0 12     68 (20)        35.4   44.8  9.4                                   10.0 18     58 (14)        36.1   37.0  0.9                                   10.0 24     48 (9)         36.6   36.6  0                                     12.5  0     182 (83)       34.7   48.5  13.8                                  12.5 12     82 (28)        35.9   45.1  9.2                                   12.5 24     55 (13)        36.3   39.8  3.5                                   12.5 36     48 (9)         36.8   37.2  0.4                                   ______________________________________                                         *R' above is C.sub.12-14 tertiary alkylmethyl, surface tension                measurements being taken at 0.1% concentration and 20° C.         

From Table 2 it can be seen that increasing the amounts of ethyleneoxide and propylene oxide in virtually all cases tended to reduce the pHsensitivity of the composition (i.e., "change" becomes smaller). Thus,the unexpected sensitivity of the present compositions over those of theRohm and Haas patents (which would have polyether chain molecularweights greater than any of the materials in the table) is seen.

The extreme pH sensitivity of the present lower molecular weightsurfactants might be attributed to the fact that the charge on thenitrogen atom resulting from protonation is less dispersed in otherpolyether material than it would be in the higher molecular weightmaterials of the Rohm & Haas patents. There simply is no recognition ofthis phenomena in these materials.

"Foam break temperatures" are measured by adding approximately 0.1% byweight of the nonionic surfactant to be tested by 3 liters of cold watercontained in a temperature-controllable, metal 3 liter beaker. Upwardlyprojecting from the rim of the metal beaker a distance of about 1 foot(30 cm) so as to contain foam generated from the water in the metalbeaker is a glass cylinder having a vertical ruler for measuring theheight of a column of foam generated therein. Disposed near the open endof the glass cylinder and directed into the metal beaker is a number30/15 "V-Jet" spray nozzle which is in communication with a pressurecontrollable water pump. The water pump circulates the contents of thebeaker through the nozzle. For purposes of the evaluation herein, apressure of 10 psi (70 kPa) was provided by the pump to the nozzle. Ashort period of time after activation of the pump, an equilibrium foamheight is produced in the glass cylinder, this equilibrium foam heightbeing characteristic of a given surfactant at a given temperature of thesurfactant-water solution. At this point, the temperature of the waterin the beaker is gradually increased, the height of the foam columnbeing recorded at approximately 5° F. intervals. The temperature atwhich the height of the foam column falls to a height of 3 inches (7.5cm) above the surface of the water in the metal beaker is defined to bethe foam break temperature for the material being tested. Thisdefinition of "foam break temperature" has been found to correlate wellwith the foam restriction ability of the material in actual paper makingprocesses.

METHODS

The methods to which the instant compositions are particularly wellsuited (although not limited thereto) are broadly in the area of thepreparation of paper and paper products from secondary fiber. "Secondaryfiber", as the term is used herein means cellulosic fiber which hasalready been converted into paper products at least once. Thus,secondary fiber includes reclaimed fiber which is paper mill processingwaste and recycled fiber which is fiber which has been at least oncecompletely converted to an intended end use and which has been returned(i.e. "recycled") for reuse. Another potential application of thepresent method is in the area of size enhancement of virgin fibergenerated from raw fiber sources such as wood.

In the preparation of paper products from secondary fiber, there aregenerally recognized two distinct processes, viz., deinking andrepulping. Both processes require an initial step where the secondaryfiber is reduced to a fiber slurry in water. This initial step herein iscalled defibering or pulping so as not to confuse it with amultiple-step "repulping" process. In the process of deinking, secondaryfiber is decontaminated, meaning that substantially all secondarycellulose fiber is separated from substantially all non-cellulosematerials or contaminants to produce decontaminated secondary fiberwhich can be employed to make white or essentially white paper. Thenon-cellulosic contaminants in any deinking process are generallycoatings, inks, "sizes" (meaning materials which tend to enhance thewater resistivity or ink receptivity of the paper product), and othercontaminants such as staples, dirt, etc.

"Repulping" processes, on the other hand, are not intended to produce apaper end-product in which the secondary cellulose fiber andnon-cellulose constituents are separated other than such as mayaccidentally or unintentionally occur during paper forming operations.Repulping simply means that the pulped secondary fiber is treated todisperse uniformly the non-cellulose materials (e.g., printing, ink,coatings) throughout the bulk of the cellulose mass. The end product ofa repulping process is a paper having some degree of print, ink,coatings, etc., uniformly dispersed throughout. In other words,repulping does not normally produce a high purity cellulosic product.

To complete the background for the methods of the present invention,deinking processes may be broken into two broad classes viz.,"flotation" and "washing". Flotation methods of deinking generallyinvolve passing a stream of air bubbles through an aqueous pulped ordefibered cellulose fiber slurry such as that which would be produced ina defibering step in a pulping process. The cellulose fiber slurrypassing through a flotation apparatus or cell (e.g., an air flotationcell) which generally has been treated with flotation agents to promotethe adhesion of ink particles to air bubbles passed therethrough. Theair bubbles rise to the top of the aqueous fiber slurry and carry theink particles with them generating a substantial amount of foam or frothwhich is then removed from the flotation cell. In "washing" methods ofdeinking, unwanted non-cellulosics, such as ink and coatings are more orless uniformly dispersed or emulsified throughout the aqueous cellulosefiber slurry there being no particular desire to form bubbles andsubsequent foam. (In fact foam and froth generally decrease washingprocess efficiency.) The objective in a washing process is to forceunwanted non-cellulosics such as ink to migrate from the cellulosicfiber into this aqueous medium and then to separate the aqueous mediumfrom the fiber. The compositions of the invention are applicable torepulping, flotation deinking, and washing deinking. The unexpectedapplicability of the instant compositions to each of these three methodsof secondary fiber treatment will now be discussed.

The first area of secondary fiber treatment in which the instantcompositions have been found to be useful is that of repulping. Asdiscussed above, repulping processes employ secondary fiber to producelower grades of paper and paper products such as industrial toweling,linear board and corrugated media. Unexpectedly, the compositions of thepresent invention have been found to be "size-safe" in repulpingprocesses.

In order to understand what is meant by "size-safe" it must beremembered that the ultimate objective of a repulping process is toproduce paper having a substantially homogeneous dispersion ofnon-cellulosic materials therethrough. In addition, since a substantialportion of repulped paper is employed to produce paper interliners andinterleaving where water resistivity is desirable, (e.g. in a papersleeve for six cans of beer), the use of conventional nonionicsurfactants in repulping has been generally avoided. Conventionalsurfactants tended to interfere with or inhibit the deposition of alumsize subsequently added. Since it is desirable for the size or sizingdeposition not to be interfered with (to enhance qualities such as inkreceptivity or water resistivity) it follows that conventionalsurfactants have not been used in the repulping processes.

To illustrate the above, Table 3 shows some Hercules Test Values (inseconds) for a number of materials tested. The number of secondsindicates the amount of time needed for a colored aqueous test fluid topenetrate a standard repulped hand sheet made employing the listedsurfactants. The greater the number of seconds needed for the water topenetrate, the better the size has been maintained on the fiber and themore water resistivity of the paper.

                  TABLE 3                                                         ______________________________________                                                               Hercules Test                                                          Lb/Ton Seconds                                                ______________________________________                                        Nonylphenol-EO.sub.9.5                                                                          Blank    70                                                   "               0.5      22                                                   "               2.0      10                                                 Nonylphenol-EO.sub.9.5 PO.sub.6                                                                 0.5      46                                                   "               2.0      10                                                 R-N--EO.sub.7.5 PO.sub.6                                                                        0.5      110                                                  "               2.0      120                                                R-N--EO.sub.10 PO.sub.12                                                                        0.5      130                                                  "               2.0      240                                                ______________________________________                                    

Thus, in one aspect, the instant invention is a repulping method forgenerating defibered, sized-enhanced, water resistant paper product fromsecondary fiber comprising the steps of agitating the secondary fiber inan aqueous, alkaline medium, comprising a composition of Formula V, saidmedium being maintained at a pH in the range of 9 to 12 and atemperature in the range of 80° F. (27° C.) to 200° F. (93° C.); wherebya fiber slurry is produced, mixing the slurry with a sizing precursor;acidifying the slurry to lower its pH in the range of about 4.5 to 6.0,so as to precipitate said size; forming a size enhanced paper web fromthe acidified slurry; drying and forming the web to produce a sizedenhanced recycled paper.

In yet another aspect the invention provides a low foam method ofdeinking secondary fiber comprising the steps of:

A. agitating sufficient secondary fiber in aqueous alkaline pulpingmedium comprising a composition of Formula V to produce a fiber slurryof up to 15% fiber by weight and emulsified and dispersed non-cellulosiccontaminants, the medium having a pH greater than 8 and a temperature inthe range of 80° F. (27° C.) to 180° F. (82° C.);

B. concentrating the slurry to a percent by weight of fiber up to 25%;whereby an aqueous effluent and a slurry concentrate are produced;

C. optionally recycling the aqueous effluent to agitating step A afterclarification by:

1. acidifying the effluent to a pH of less than 8 thus causingemulsified materials to de-emulsify.

2. adding a flocculating agent to said effluent whereby de-emulsifiednon-cellulosic materials can be separated from the effluent.

3. adding base to the clarified effluent.

D. separating non-cellulosic contaminants in the slurry concentrate fromthe cellulosic fiber in the concentrate by deinking; and

E. forming the cellulosic fiber into paper.

In a preferred practice of the above method, D is accomplished by:

1. acidifying the concentrate to a pH of less than about 8;

2. passing the acidified slurry through a flotation cell; and

3. optionally increasing the pH of the slurry and passing it through awashing step.

It is to be noted that the above deinking method has an optionalrecycling step "C". This optional step is referred to in the art as"hot-loop clarification". In the parlance of technology, the hot-loopapparatus consists of the pulping or defibering apparatus, the dumpchest, a cleaner, a means to concentrate the slurry up to 25% fiber(e.g., a decker), a clarification system to add clarifying flocculants,along with a return means which attempts to recycle some of theexpensive chemicals and water generated in the concentation step to thestart of the pulping process. The initial pulping step occurs by meansof agitation in a high shear environment provided by the pulper with orwithout other pulping aids. Temperatures in the range of 80° F. (27° C.)to 180° F. (82° C.) are employed along with caustic (NaOH,) otherdefibering or pulping chemicals (called pulping aids) as well asconventional nonionic surfactants have been employed in this pulpingstep. "Hot-Loop Clarification" amounts to removal of unwantedcontaminants of materials in the hot loop stream so as to clarify andremove unwanted materials therefrom. Clarification of the cooking liquor(as it is called) after the concentration step is normally accomplishedby adding a high molecular weight (e.g., one million or more)flocculating agent or flocculant, thus precipitating opacity-producingmaterials. As practiced in pulping, compositions of the presentinvention maintained are at a pH in the range of 9 to 12 and at atemperature of about 80° F. to about 180° F. In a preferred practice oneor more other pulping aides are used to defiber the secondary fibersource. After pulping, or defibering the hot mass is treated with acidto decrease its pH to the range of 8 or less. This decrease in pH tendsto cause the surfactants to loose their emulsification propertiesresulting in the pulping liquor being separated into an aqueous phase(along with the surfactants of the invention) and a substantiallynon-aqueous phase of unwanted contaminants. At this point, the unwantedcontaminants maybe separated from the processing stream and discarded.Having thus clarified the hot loop by pH adjustment, this aqueousmixture then is returned to the start of the processing stream. In thismanner expensive chemicals are recycled and unwanted contaminants areremoved from the processing line thus "clarifying" the loop. The aqueousphase containing the surfactants of the invention then is treated withbase to deprotonate the amine functionality to provide the highemulsification properties characteristic of nonionic surfactants.

As noted, the compositions of the present invention also haveapplications in deinking processes where the desired end result issubstantially reusable white paper. Polypropoxylation (or benzylation)of single chain alkylamine polyethylene oxide polyethers providesnonionic surfactants which can be employed in both washing and flotationdeinking processes. This universality of application also originates inthe pH sensitivity of the instant compositions. For example, ifmaintained at a high basic pH range, the instant nonionic surfactantshave little or no foaming tendency depending upon the extent of PO orterminal block and the temperature at which they are employed. This isimportant in the initial pulping step because excessive foam at thispoint merely serves to decrease pulping efficiency. Excess foaming ortendency to foam also leads to air entrained in the processing streamwhich again decreases overall efficiency of the pulping process. Thepropoxylated or benzylated materials of the invention providesubstantial advantages over the "PR and Priminox" Series of materialscommercially available from Rohm and Haas Company in that they havesubstantially less foaming tendency than these materials. Thus it iscritically important to the increase in the efficiency of repulping thatpropoxylation and benzylation occur. No mention of this increase inefficiency is made in any of the literature available relating to thesematerials.

Subsequently, by selective downward adjustment of the pH, it has beenfound possible to adjust very precisely the foaming tendency or foamstability of the medium containing the compositions of the invention. Inother words, the compositions of the invention by means of pH adjustmentcan be employed successfully in washing-type deinking processes wherelittle foaming tendency is required and flotation-type processes wheresubstantial foaming tendency is required. Both of these previouslymutually exclusive goals are met by the expedient of pH adjustmentemploying surfactants of the present invention.

The instant invention will now be illustrated by reference to a seriesof examples which are intended to be illustrative and not limiting.

EXAMPLE I

Illustrating the use of compositions of the present invention in papermaking in both washing and flotation-type deinking processes.

Secondary fiber consisting of 50% ground wood free book and 50% printedledger was added at a 5.5% fiber consistency to a "Morden Slush Maker"pulper. Fifteen hundred gm of the fiber stock, 15 gm of 50% caustic (1%of fiber) and 4.5 cc of the specified pulper additive (0.3% of fiber)also were added to the pulper. Pulping was done at 140° F. (60° C.) for3 minutes followed by 40 minutes at no agitation and then a 30 secondfinal pulping "burst". The sixteen hundred ml slurry so produced in thepulper then was diluted to 15,000 ml (0.6 concentration) for processingthrough a flotation cell. The Voith Morden 17 liter flotation cell had arecirculating pump and an air injection system that generates foam tolift unwanted ink through the surface of the aqueous stream. In order tofacilitate comparison between stocks generated in a flotation cell andthose generated by washing, under surface stock samples were withdrawnfrom the flotation cell every four minutes for a total of 20 minutes andwere converted into hand sheets. After a 20-minute period of repulping,an end-product sample was washed on a side hill screen (a washing-typedeinking step) 3 times and then converted to a hand sheet. The handsheets generated during the flotation cell process were compared to thehand sheets of the stock from the pulper (i.e., with no washing orflotation deinking) after having traversed three side hill washers. Thedata generated in this run is summarized in Table 4.

                                      TABLE 4                                     __________________________________________________________________________                                                        Bright-                                    Unwashed                                                                            Brightness Brightness Values After                                                                         ness After                Pulper       (% on                                                                             Pulp  After      (Minutes)         3 Washes                  Run                                                                              Additive  fiber)                                                                            Brightness                                                                          3 Washes                                                                            Change                                                                             4   8  12  16 20  (flotation)                                                                         Change              __________________________________________________________________________    1  Soap      0.3 59.5  67.3  7.8  68.3                                                                              69.2                                                                             69.7                                                                              70.5                                                                             71.2                                                                              75.0  15.5                2  Soap +    0.3 62.8  70.5  7.7  69.3                                                                              72.0                                                                             72.8                                                                              73.0                                                                             73.1                                                                              77.9  15.1                   Nonyl-                                                                        phenol-                                                                       EO 9.5                                                                     3  Nonyl-    0.3 60.3  67.9  7.6  64.7                                                                              68.3                                                                             69.5                                                                              71.1                                                                             71.4                                                                              75.2  14.9                   phenol-                                                                       EO 9.5-                                                                       PO 6                                                                       4  Nonyl-    0.3 61.7  67.6  5.9  59.9                                                                              63.8                                                                             62.3                                                                              64.5                                                                             63.9                                                                              75.0  13.3                   phenol-                                                                       EO 9.5-                                                                       PO 24                                                                      5  R.sub.1 --NH--                                                                          0.3 60.9  69.4  8.5                                                 (EO)).sub.10                                                                  (a) pH 6.0                     66.6                                                                              68.1                                                                             69.8                                                                              69.3                                                                             --  74.5  13.6                   (b) pH 4.5                     64.0                                                                              65.3                                                                             68.3                                                                              68.6                                                                             --  73.0  12.1                   (c) pH 8.0                     66.1                                                                              66.7                                                                             67.5                                                                              -- --  74.5  13.6                6  Soap +    0.3 58.7  70.9  12.2 66.9                                                                              70.3                                                                             71.2                                                                              71.1                                                                             70.6                                                                              77.5  18.7                   R.sub.1 --NH--(EO).sub.10                                                  7  R.sub.1 --NH--                                                                          0.3 63.7  71.5  7.8                                                 (EO).sub.10 --                                                                PO.sub.6                                                                      (a) pH 4.5                     67.6                                                                              70.1                                                                             71.5                                                                              72.9                                                                             71.6                                                                              78.2  14.5                   (b) pH 8.0                     70.0                                                                              71.0                                                                             71.7                                                                              71.5                                                                             70.5                                                                              78.1  14.4                8  R.sub.1 --NH--                                                                          0.3 63.4  73.1  9.7                                                 (EO).sub.10 --                                                                PO.sub.12                                                                     (a) pH 4.5                     70.0                                                                              71.9                                                                             72.5                                                                              73.8                                                                             75.3                                                                              80.3  16.9                   (b) pH 8.0                     69.7                                                                              73.0                                                                             73.2                                                                              73.0                                                                             73.0                                                                              79.6  16.2                __________________________________________________________________________     Notes to Table 4                                                              Brightness values are as measured on a Hunter Reflectometer.                  R.sub.1 is a C.sub.12 -C.sub.14 tertiary alkyl hydrophobe.               

Soap in runs 1, 2 and 6 was made in situ using a commercially availabletall oil fatty acid available from Union Camp as Unitrol DSR 90neutralized with sodium hydroxide.

Runs 7 and 8 are compositions of the present invention. In both cases,brightness values obtained in this flotation run were better at thelower pH (i.e. 4.5). Furthermore, performance (as indicated by thebrightness values) was better in the higher propoxylated materials. Inother words, the brightness values obtained after sixteen minutes offlotation deinking were 78.8 for material having 12 moles of propyleneoxide, 72.9 for material having 6 moles or propylene oxide, and 68.6 formaterial having no propoxylation.

One skilled in the flotation art will recognize that composition 2 inTable 4 is a conventional industry-standard flotation aid. It iscritically important to note that the compositions of the invention(i.e. compositions of run 7 and 8) indicate (in the "change" last columnof Table 4) that the compositions of the invention produce a brightnessincrease which is better than or equal to materials presently available.It is to be noted that roughly half as much material is employed in eachof the runs of the invention vs. the industry standard compositions.Thus a cost advantage is obtained. Perhaps more importantly, theindustry standard flotation aid containing soap is commonly employed soas to produce a soap "scum" which is referred to in the industry as acalcium soap, water insoluable collector. In operation, nonionicsurfactant bubbles lift water and insoluable soap, to which is attacheddislodged ink particles. Thus, the insoluable soap scum containing theink particles may be drawn from the flotation cell. The disadvantage ofthis variety of flotation aid is two-fold. First, residual soap from theflotation stage can cause deposit problems in subsequent stages of thedeinking process. Second, if combinations of washing and flotationdeinking processes are employed (as is common in the United States),residual soap can cause foaming problems which interfere with properdrainage in subsequent washing stages.

EXAMPLE 2

Illustrating utilization of the present compositions in flotationdeinking.

Hand sheet brightness of three different compositions in flotationdeinking was compared in an industrial environment. The threecompositions were:

1. Nonylphenol EO₉ -PO₆ ;

2. A low-foaming nonionic surfactant as in 1 plus butyl cellosolve plusan acrylic acid polymer polyelectrolyte; and

3. A trialkylmethylamine-EO₁₀ -PO₁₂ of the invention.

The above compositions were evaluated for flotation deinkingcapabilities as described below.

First a furnish of printed government document grade secondary fiber(i.e., a secondary fiber source) was pulped at a temperature at 120° F.(49° C.) and pH of 11.0 for a time period 5 minutes in a kitchenblender. This fiber stock was used in all the experiments hereindescribed. Before any sodium hydroxide or any other deinking aid wasadded to the fiber stock, a sample was withdrawn and a hand sheet madetherefrom as a start up reference for each of three pulper batches.Next, sodium hydroxide (beaded) at 1% by weight and the respectivedeinking chemical was added to the fiber stock. The deinking compositiontested was added at the rate of 22 ml per four pounds fiber orapproximately 20 pounds deinking composition per ton of fiber. Therepulped fiber stock containing the deinking composition and sodiumhydroxide was allowed to circulate through a flotation cell commerciallyavailable from Bird Equipment Company for a time period of 30 minutes. ApH in the range of 10.5 or 11.5 was employed (except during a pHsensitivity test in which case it was lowered to 7.0), a temperature inthe range of 65° F. (24° C.) to 75° F. (68° C.) and a fiber consistencyof approximately 6% also was utilized. The foam generated by theflotation apparatus was collected and used to make hand sheets labeled"rejects". Hand sheets labeled "accepts" also were made by periodicallywithdrawing samples from the flotation cell. The results of thiscomparative evaluation are described in Table 5.

                  TABLE 5                                                         ______________________________________                                               Composition                                                                   1          2          3                                                       pH                                                                                                  10.8 initially                                                                then acidified                                          10.8       10.8       to 7.0                                           ______________________________________                                        Ink Particles                                                                 Start-Up Few distinct Many distinct                                                                            Several dis-                                          ink specks on                                                                              black ink  tinct black                                           a gray back- specks on a                                                                              ink specks                                            ground       gray back- on a gray                                                          ground     background                                   Accepts  Few, small   Few, small Few, small ink                                        specks       specs larger                                                                             specks, less                                                       than for com-                                                                            than for com-                                                      position 1 position 1                                   Rejects  Light gray back-                                                                           Medium gray                                                                              Dark gray                                             ground       background.                                                                              background.                                                        Many small Many large                                                         distinct   distinct ink                                                       specs      specs                                        Foam     Very thick and                                                                             Stable and Loose, frothy,                               Charac-  stable. Ex-  thick. Man-                                                                              unstable,                                    teristics                                                                              tremely diffi-                                                                             agable     easily manag-                                         cult to man-            able                                                  age                                                                  Brightness                                                                    (Hunter Lab)                                                                  (a) Start-up                                                                           60.08        57.99      54.75                                        (b) Accepts                                                                            66.62        64.63      65.70                                        (c) Rejects                                                                            58.97        48.33      41.56                                        b-a       6.54         6.64      10.95                                        b-c       7.65        16.30      24.26                                        ______________________________________                                         Note: Handsheets were examined under magnification to evaluate ink            particle size, distribution across the sheet, and general sheet quality. 

Based on the information described in Table 5, it is clear thatcomposition 3 (the composition of the invention) is the most effectivedeinking composition for use in the flotation deinking cell among thosetested. The foam generated employing compositions of the invention arevery unstable forming large fluffy bubbles which collapse quickly uponremoval of a sample from the flotation cell. This is one of theadvantages of the invention, namely, the unstable foam permitsutilization of smaller storage and conveyance facilities for the foamdrawn from the flotation cell.

Further confirmation is obtained from the Hunter laboratory evaluationof the hand sheets generated from flotation deinking fiber stock. Undercomposition 3 it is found that the difference between the "accepts" and"rejects" is approximately 24 Hunter laboratory brightness units. Forcomposition 2 it is approximately 16 and for composition 1 it isapproximately 7. It follows that the compositions for the presentinvention provide an increase in brightness of from about 300 to about150% of conventional flotation aids. This presents a substantialadvantage neither described nor suggested in any of the art dealing withthis technology.

The above example was intended to illustrate the instant invention. Oneskilled in the art will recognize several alternatives and variationswhich should be included within the scope hereof.

EXAMPLE III

To illustrate the additional foam control obtainable in a practice ofthis invention, reference is made to tables 6, 7, and 8. Table 6 showsthe effect of propoxylation on foam break temperature for a number ofamine polyethers. Table 7 illustrates the effect of propoxylation onfoam stability for the same compositions listed in Table 6. Table 8illustrates the effect of temperature on foam stability for a specifict-C₁₃ -NH-EO₁₀ -PO₁₂ H listed in Tables 6 and 7.

                  TABLE 6                                                         ______________________________________                                        EFFECT OF ETHOXYLATION/PROPOXYLATION                                          ON FOAM BREAK TEMPERATURES                                                    t-C.sub.13 --NH--(C.sub.2 H.sub.4 O).sub.m (C.sub.3 H.sub.6 O).sub.n H        m       n          Foam Break Temp. °F. (°C.)                   ______________________________________                                        7.5      0           136° F.                                                                         (58)                                            7.5      6         77         (25)                                            7.5      9         67         (19)                                            7.5     12         56         (13)                                            7.5     18         50         (10)                                            10.0     0         165        (74)                                            10.0     6         97         (36)                                            10.0    12         68         (20)                                            10.0    18         58         (14)                                            10.0    24         48          (9)                                            12.5     0         182        (83)                                            12.5    12         82         (28)                                            12.5    24         55         (13)                                            12.5    36         48          (9)                                            ______________________________________                                    

                  TABLE 7                                                         ______________________________________                                        EFFECT OF ETHOXYLATION/PROPOXYLATION                                          AND pH ON DYNAMIC FOAM GENERATION                                             t-C.sub.13 --NH--(C.sub.2 H.sub.4 O).sub.m (C.sub.3 H.sub.6 O).sub.n H        pH 12.0               pH 6.0                                                  Foam Height in inches Foam Height in inches                                   m    n     110° F.*                                                                        80° F.**                                                                      50° F.***                                                                     110° F.80° F.50°       ______________________________________                                                                          F.                                          7.5   0    8        8      8      all                                         7.5   6    0        3      8                                                  7.5   9    0        0      8                                                  7.5  12    0        0      4                                                  7.5  18    0        0      3      at                                          10.0  0    8        8      8                                                  10.0  6    0        8      8                                                  10.0 12    0        0      6                                                  10.0 18    0        0      6                                                  10.0 24    0        0      2      4-6 inches                                  12.5  0    8        8      8                                                  12.5 12    0        3      8                                                  12.5 24    0        0      4                                                  12.5 36    0        0      1                                                  ______________________________________                                         *110° F. = 43° C.                                               **80° F. = 26° C.                                               ***50° F. = 10° C.                                         

                  TABLE 8                                                         ______________________________________                                        EFFECT OF TEMPERATURE AND pH ON                                               DYNAMIC AND STATIC FOAM OF                                                    t-C.sub.13 NH(C.sub.2 H.sub.4 O).sub.10 (C.sub.3 H.sub.6 O).sub.12 H          T, °F.                                                                              Dynamic  Static                                                  Temp. pH     Foam Ht. Foam Ht. 5' min.                                                                         Seconds to 0 Foam                            ______________________________________                                        110°                                                                         10     0        0           0                                           110°                                                                         8      0        0           0                                           110°                                                                         6      6        0          30                                           110°                                                                         4      6.5      0          50                                           80°                                                                          10     0        0           0                                           80°                                                                          8      0        0           0                                           80°                                                                          6      6        0          30                                           80°                                                                          4      6.5      0          50                                           50°                                                                          10     8        4          300                                          50°                                                                          8      8         21/2      300                                          50°                                                                          6      5.5      0          20                                           50°                                                                          4      6        0          40                                           ______________________________________                                    

To illustrate how Tables 6 and 7 may be read together to show the addedfoam control parameters provided by the present invention, take, forexample, the first listed material in each table. This material would bea trialkylmethylamine having 13 carbon atoms in its hydrophobic portion.The secondary amine links the hydrophobic portion and an average of 7.5moles of ethylene oxide. As listed in Table 6, the foam breaktemperature for the material is 136° F. (58° C.). Looking at Table 7,and measuring the foam height at 110° F. (43° C.), 80° F. (26° C.), and50° F. (10° C.), it is found that each measurement produces a foamheight of 8 inches or more. This is true because the measurementtemperatures are each below the 136° F. (58° C.) foam break temperatureof the composition. Focusing upon the next listed material having 7.5moles of ethylene oxide, 6 moles of propylene oxide, with a foam breaktemperature of 77° F., it is found that foam height at 110° F. is zero.At 80° F., near the foam break temperature, a relatively small threeinch column of foam is generated. At 50° F. (i.e. substantially belowthe 77° F. foam break temperature), roughly an 8 inch head of foamresults. Similarly, in the -EO₁₀ H and (EO)₁₂.5 H species where the foambreak temperatures are 165° F. and 182° F. respectively, the foamheights at 110°, 80° and 50° are all in excess of 8 inches.

The addition of a relatively small amount of propylene oxide to theethylene oxide polyether brings about a substantial reduction in thefoam break temperature. For example, the addition of 6 moles ofpropylene oxide to an alkylamine polyether having 10 moles of ethyleneoxide reduces the foam break temperature to 97° F. Thus, at 110° underthe pH 12.0 column, foam height is essentially zero while at 80° and50°, the foam height is in excess of 8 inches.

Turning to the pH 6.0 column of Table 7, it is indicated that allspecies therein provide a foam height in the range of 4 inches to 6inches. It is to be remembered that at this pH, the compositions of theinvention will be essentially quaternized (that is, they have beenprotonated). Quaternization substantially reduces the effect ofpropoxylation with respect to the foam characteristics of the molecule.Furthermore, the foam generated for each of these materials in this pHrange is unstable, fluffy and very amenable to collapse. This isillustrated in Table 8 where both the extent of foaming and itsstability is explored for a single material from Tables 6 and 7.

Table 8 indicates for three different temperature ranges and fourdifferent pH ranges, foam height and foam stability. For example, at110° F. at a pH of 8-10, zero foam is generated. This evidences theeffect of propoxylation of the ethyloxated alkylamine. Furthermore, aspH is dropped from approximately 8 to approximately 6, the tableindicates that the effect of propoxylation is mitigated. It should benoted that this is the "dynamic foam height". Dynamic foam heightdiffers from "static foam height" in that the spray mechanism isshut-off in the latter. Once the spray mechanism is shut-off at pH's inthe range of 6-8, the foam very rapidly collapses. Thus, reading acrossfrom the 110° F. column at a pH of 6, dynamic foam height of 6 and foamheight after 5 minutes of zero would be a 6 inch column having collapsedto zero in roughly 30 seconds. Similarly, at a pH of 4, roughly 50seconds are required after the spray mechanism is shut-off for the foamheight to collapse to zero.

This is a critically important aspect of the methods of the instantinvention. In essence, the ability to control dynamic and static foam asa function of pH and operating temperature, means that in the papermaking process an additional parameter for foam control has beenidentified. Employing the compositions of the present invention papermaking on the alkaline side, foam is strictly dependent upon thepresence or absence of propylene oxide (or its equivalent). On the acidside, the influence of propylene oxide on foam characteristics is nolonger found. It is found that the presence or absence of foam (and itsstability) is strictly dependent upon pH. This means that in deinkingprocesses employing either flotation, washing or a combination of steps,the extent and stability of foam can be controlled by adjustment of pH,temperature or both.

Thus, where large amounts of stable foam are desired, selection of anappropriately propoxylated alkylamine or operating temperature below thefoam break temperature would be desirable. Where a less stable, frothyfoam is desired, adjustment of pH would be in order. By this it is seenthat an additional parameter controlling the extent and stability offoam has been identified.

What is claimed is:
 1. A foam controllable, pH sensitive alkylaminepolyether of the structure: ##STR19## wherein (a) R₁ is alkyl and R₂, R₃and R₄ are alkyl or hydrogen, the total number of carbon atoms in R₁ +R₂+R₃ +R₄ falling in the range of 7 to 36;(b) The --(C₂ H₄ O)_(m) --segment must be a poly(oxyethylene) homogeneous chain or block polymer,m having an average value in the range of 5-13; and (c) Y is ahomogeneous poly(oxypropylene) chain block polymer, of the structure--(C₃ H₆ O)_(n) H, n having an average value in the range of 6-30. 2.The polyether according to claim 1 wherein the total number of carbonatoms in R₁ +R₂ +R₃ +R₄ falls in the range of about 10 to
 20. 3. A foamcontrollable, pH sensitive alkylamine polyether of the structure:##STR20## wherein (a) R₁ is hydrogen;(b) R₂, R₃ and R₄ are at leastmethyl groups, the total carbon atoms of R₂ +R₃ +R₄ falling the range of7 to 23; (c) the --(C₂ H₄ O)_(m) -- segment must be a poly(oxyethylene)homogeneous chain block polymer, m having an average value of 10; and(d) the --(C₃ H₆ O)_(n) -- segment must be a homogeneouspoly(oxypropylene) chain block polymer, n having a value in the range of6-24.
 4. The polyether according to claim 3 wherein R₂ +R₃ +R₄ have atotal number of carbon atoms in the range of 12 to
 22. 5. The polyetheraccording to claim 3 wherein m is 10 and n is 6-24.